Spool assembly

ABSTRACT

A spool assembly having a spider-shaped core on which an exterior tube is structurally supported, with the tube retained on the core between end plates. The core has longitudinal ribs projecting radially outward for support of the tube at outer edges of the ribs, which are formed with spaced walls that define longitudinal slots in which self-tapping screws engage to secure the end plates to the core. The rib walls may converge outwardly to confine the screws in the slots and form an acute angle with the interior surface of the tube so that the tube will retain the walls against spreading by the screws, for which purpose also the tube has grooves for seating of the ribs therein and annular reinforcing discs are disposed adjacent the ribs at the ends of the core. The tube may have a free length slightly longer than the core so that it will be prestressed in compression by securement of the end plates to the core with the tube between the end plates. Portions of the outer surfaces of the rib walls can be contoured for substantially flush engagement with the interior surface of the tube, and one wall of each rib may be formed with a thin sizing that can be cut back to a dimension that will provide with the other rib walls a snug fit with the tube interior. The spider-shaped core may be either of unitary, integral construction, or formed of separate elements that can be selectively assembled to form cores of varying characteristics from a minimum inventory of different elements.

United States Patent [191 Poteat May6, 1975 SPOOL ASSEMBLY [75] Inventor: George A. Poteat, Greensboro, NC.

[73] Assignee: Engineered Plastics, Incorporated,

Gibsonville, NC.

[22] Filed: Aug. 27, 1973 [21] Appl. No 391,955

Related U.S. Application Data [63] Continuation-impart of Ser. No. 318,515, Dec. 26,

1971, abandoned.

Primary ExaminerGeorge F. Mautz Attorney, Agent, or Firm-Richards, Shefte & Pinckney ABSTRACT A spool assembly having a spider-shaped core on which an exterior tube is structurally supported, with the tube retained on the core between end plates. The core has longitudinal ribs projecting radially outward for support of the tube at outer edges of the ribs, which are formed with spaced walls that define longitudinal slots in which self-tapping screws engage to secure the end plates to the core. The rib walls may converge outwardly to confine the screws in the slots and form an acute angle with the interior surface of the tube so that the tube will retain the walls against spreading by the screws, for which purpose also the tube has grooves for seating of the ribs therein and annular reinforcing discs are disposed adjacent the ribs at the ends of the core. The tube may have a free length slightly longer than the core so that it will be prestressed in compression by securement of the end plates to the core with the tube between the end plates. Portions of the outer surfaces of the rib walls can be contoured for substantially flush engagement with the interior surface of the tube, and one wall of each rib may be formed with a thin sizing that can be cut back to a dimension that will provide with the other rib walls a snug fit with the tube interior. The spider-shaped core may be either of unitary, integral construction, or formed of separate elements that can be selectively assembled to form cores of varying characteristics from a minimum inventory of different elements.

34 Claims, 16 Drawing Figures PATENTEDHAY 6l975 SHEU 10F 5 PATENTEUMY 61915 SHEET 5 BF 5 A I ug SPOOL ASSEMBLY CROSS-REFERENCES TO RELATED APPLICATIONS BACKGROUND OF THE INVENTION The present invention relates to a spool assembly and more particularly to a spool assembly of the type having a core that provides the structural support for an exterior tube on which material is to be wound.

A conventional spool assembly has a solid body with an integral or separate exterior surface formed or finished for winding of material thereon. Being solid, this type of spool assembly is relatively expensive and heavy, the latter resulting in relatively high power requirements for rotation in a winding operation.

To avoid the disadvantages of solid spool assembly constructions, various hollow spool assemblies have been designed. For example, Markle Canadian Patent No. 460,596, issued Oct. 25, 1949, discloses a barrel having a cylindrical shell and a central core connected by integral ribs, a sleeve seated on the shell to provide a winding surface, and end plates secured to the barrel by screws seated in slots in the periphery of the barrel and also threaded in the adjacent portions of the sleeve. This construction, though lighter than a solid spool assembly, has both a cylindrical shell and a cylindrical sleeve and the sleeve must be of sufficient strength to retain the screws in the exposed slots of the core. Other examples of hollow spool assemblies are found in Hutchinson US. Pat. No. 3,650,494, issued Mar. 21,

1972, and Jones US. Pat. No. 3,614,018, issued Dec. 29, 1969, both of which disclose cylindrical barrels that are themselves completely hollow and extend unsupported throughout substantially their full length, with end plates secured to the barrel ends by end plugs with screws threaded into both the end plugs and the inner surface of the barrels. In these constructions the barrels must be strong enough to support the wound material without interior support, and the screws must be secured to the barrel sufficiently to prevent separation as securement to the end plugs alone will not retain the parts in assemblage.

SUMMARY OF THE INVENTION By the present invention a spool assembly is provided that is lightweight and inexpensive to produce and yet has necessary strength characteristics. By using a lightweight core and designing it so that it structurally supports an exterior tube, an inexpensive and lightweight tube may be used. This is made possible by using fastening means uniquely seated in peripheral core slots in a manner that retains the fastening means securely in the core slots without appreciably affecting the inexpensive and lightweight features of the construction.

Briefly described, the spool assembly of the present invention includes a spider-shaped core that has an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from the center portion. Each rib has an outwardly opening longitudinal slot defined by spaced walls extending along the outer edge of the rib. An exterior tube is mounted on and structurally supported by the core at the outer edges of the walls. End plates are disposed at each end LII of the core and extend radially outward to the tube for retention of the tube on the core between the plates. The end plates and core are fastened together by means secured in the core rib slots.

In one embodiment, the core extends substantially the full length of the spool assembly for structural support of the tube throughout substantially its full length, the walls of each rib converge outwardly to at least partially close the slot over the fastening means, and the fastening means is secured substantially fully in the slot, thereby supporting the tube on the core without tube deforming engagement by the fastening means. Preferably, the rib walls engage the tube at acute angles exteriorly of the slot so that the tube retains the rib walls against spreading, thereby maintaining the fastening means secured in the core. rib slot.

In another embodiment an annular reinforcing member is located at each end of the core and adjacent the rib walls to reinforce the rib walls against spreading and thereby retain the fastening means in the core slot. The reinforcing member may be a flat disc disposed between the core and end plate and recessed to receive the rib walls for reinforcement thereof, preferably with the core ribs recessed between the center portion and the rib walls to receive the disc thereon and with the disc having flanges extending therefrom along the rib walls inwardly from theends thereof to strengthen the rib wall reinforcement.

In the foregoing embodiments, the core may be formed with a separate center portion and a plurality of longitudinal ribs, each of which is formed as a separate element, and the annular reinforcing member at each end of the center portion engages and supports the ribs at positions projecting radially outward from said center portion. The annular reinforcing member is formed with notches for engaging the ribs, whereby all of the separate elements of the core are held together in proper relation to one another, yet these separate elements are capable ofbeing readily and selectively assembled or disassembled to form cores of different characteristics from a relatively small inventory of parts.

In a further embodiment, the tube has longitudinally extending inwardly opening grooves formed in its interior surface for seating therein of the outer ends of the rib walls to reinforce the ribs walls against spreading and thereby retain the fastening means in the slots. Preferably, the tube is enlarged adjacent the grooves to provide a formation for the grooves, and the interior surface of the tube is generally cylindrical with chordal portions in which the grooves are formed.

In the preferred embodiment either the aforementioned grooved tube or the converging rib wall feature is combined with the reinforcing disc, and the fastening means and tube are in nonengaging relation so that the tube is not deformed by the fastening means, which is in the form of self-tapping screws extending through the adjacent end plates and tapped into the rib slots with their centers spaced from each rib wall and slot base a distance equivalent to the minor radius of the screws for positive and firm securement in the slots. Also, the tube has a free length slightly longer than the core so that the tube is prestressed in compression between the end plates for greater strength in supporting wound material thereon. Further, the outer surfaces of the rib walls are contoured for substantially flush engagement with the interior surface of the tube, and one wall of each rib is formed with a thin sizing ridge formed along its outer edge and projecting for cutting back as required in combination with the other rib walls to provide a relatively snug fit of the tube on the core.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective elevational view of a preferred embodiment of the spool assembly of the present invention;

FIG. 2 is a bottom view of the spool assembly of FIG.

FIG. 3 is a plan view of the spool assembly of FIG. 1;

FIG. 4 is a vertical sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is an enlarged horizontal sectional view taken along line 55 of FIG. 4 and illustrating only the core, reinforcing disc, and screws;

FIG. 6 is an enlarged horizontal sectional view of an end portion of one core rib and the adjacent tube portion;

FIG. 7 is an exploded perspective view of the spool assembly of the preceding figures;

FIG. 8 is an enlarged perspective view of a portion of the core rib of the preceding figures;

FIG. 9 is a vertical sectional view, partially broken away, showing the parts of the spool assembly of the preceding figures assembled prior to fastening of the screws and exaggerated to illustrate the length of the tube greater than the length of the core which results in prestressing of the tube in compression when the screws fasten the end plates on the core;

FIG. 10 is a horizontal sectional view of another preferred embodiment of the spool assembly of the present invention taken through the tube, core and screws;

FIG. 11 is a perspective view of a portion of the tube of the spool assembly of the embodiment of FIG. 10;

FIG. 12 is a horizontal sectional view of a further preferred embodiment of the spool assembly of the present invention taken through the screws and facing the end of the core and adjacent reinforcing disc;

FIG. 13 is an exploded perspective view of the screws, reinforcing disc, core and tube at one end of the spool assembly of FIG. 12;

FIG. 14 is a vertical elevation, partially broken away, of a variation of the other embodiments of the spool assembly of the present invention;

FIG. 15 is a horizontal sectional view of the spool assembly illustrated in FIG. 14, taken along line l5-15 thereof; and

FIG. 16 is an exploded view of an end portion of the spool assembly like that illustrated in FIG. 14.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the preferred embodiments illustrated in the accompanying drawings, the spool assembly of the present invention is in the form of a bobbin 20 on which carpet yarn is wound to form a package. Exteriorly, this bobbin 20 has the same general appearance as a conventional carpet yarn bobbin, and this exterior appearance, as seen in FIGS. 1-3, is the same for all of the preplate or drive flange 26 at the bottom of the core 22 and an end plate or top flange 28 at the top of the core. The flanges 26 and 28 are fastened to the core 22 by screws 30 to maintain the parts of the bobbin 20 in assembled condition.

The drive flange 26 extends substantially outward radially beyond the periphery of the tube 24 for support of yarn thereon and has a notch 32 on its periphery for protected disposition of an end of yarn from the package on top of the flange to a retaining clip 34 on the under side of the drive flange 26. To provide for driving connection of the bobbin to a winding frame or other equipment, the drive flange 26 is provided with a diametrical slot 36 on its under side, and to balance the bobbin against wobbling during high speed rotation for uniform package formation and yarn tensioning, weights 38 are pressed into the underside of the drive flange 26. Similar weights 38 may also be applied to the top side of the top flange 28, from which extends a cylindrical lift knob 40. The top flange 28 also extends radially outward beyond the periphery of the tube 24 and cooperates with the drive flange 26 for retention of the tube on the core 22 between the flanges 26, 28.

In the embodiment of FIGS. 4-9, the core 22 extends substantially the full length of the bobbin 20 and has an axially extending center portion 42 of cylindrical configuration with an axial bore 44 of uniform crosssection for receipt of a spindle when the bobbin is mounted in a winding frame or other equipment. As the bore 44 extends the full length of the bobbin, concentrated spindle wear is minimized and the bobbin is adaptable for use on spindles of varying length without any special adaptation being necessary for this purpose.

The core 22 is spider-shaped, having four equally spaced longitudinal ribs 46 projecting radially outward from the center portion 42 and extending along substantially the full length of the core 22 to provide structural support for the tube 24. This rib construction provides necessary strength while utilizing a minimum of material so that the core is relatively lightweight. Furthermore, the full length structural support of the tube 24 provided by the core rib construction results in the core carrying substantially all of the load, allowing the use of a relatively thin tube 24, which further minimizes the weight of the bobbin 20. This reduced weight and the simplified construction also reduces significantly the expense of material, production, and assembly.

Each of the ribs 46 is formed with its radially outward end bifurcated to provide spaced longitudinally extending walls 48 that define therebetween an outwardly opening longitudinal slot 50 extending substantially the full length of the core 22 along the outer edge of the rib 46. The walls 48 of all of the ribs 46 provide structural support for the aforementioned tube 24 when the tube is mounted on the core 22 and the slots 50 serve for receipt of the aforementioned screws 30 that retain the parts of the bobbin in assembled condition.

The screws 30 are preferably of the self-tapping type and extend through holes 52 in the drive flange 26 and top plate 28 that are aligned with the core rib slots 50. These screws 30 are centrally disposed in the slots 50 and are dimensioned in relation to the slots so that the center of each screw 30 is spaced from each wall 48 and from the slot base 54 a distance substantially equivalent to the minor radius of the screw so that the screw will be tapped uniformly into the core rib walls 48 and slot base 54. To facilitate fastening by the screws 30 and to assure adequate securement of the screws 30 in the slots 50, the opposing walls 48 of each rib 46 converge outwardly to at least partially close the slot over the screw 30. In the embodiment illustrated in FIG. 4-9, each wall 48 extends at an angle of about to the radial center line of the rib 46. This inclination not only results in the converging closing of the slot over the screw, but it also results in the rib walls 48 engaging the interior surface of the tube 24 at acute angles exteriorly of the slot so that the tube 24 will retain the walls 48 against spreading, thereby maintaining the screws 30 secured in the core rib slots 50. With this arrangement the screws 30 are securely retained against removal by positive means other than simply the strength and rigidity of the rib walls 48 themselves, and, therefore, a relatively light and thin rib wall construction can be utilized with unusual strength characteristics.

To further reinforce the rib walls 48 against spreading and to reinforce the ends of the tube 24 against inward deformation due to load stresses, an annular reinforcing member, in the form of a flat disc 56, is disposed at each end of the core 22 between the core and the adjacent flange 26, 28. These discs 56 are circular with their peripheries supportingly disposed at the inner surface of the tube 24 and adjacent the rib walls 48, at which they are recessed, as at 58, to receive the rib walls 48 for reinforcement thereof. To accommodate the discs 56 in reinforcing disposition with respect to the rib walls 48, the core ribs 46 are recessed longitudinally, as at 60, between the walls 48 and the center portion 42 for receipt of the discs 56 therein. In addition, the discs 56 have central bores 62 for mounting of the discs 56 on the center portion 42 of the core 22.

As the core 22 extends the full length of the bobbin between the flanges 26 and 28, securement of the parts together is accomplished solely and simply by attachment of the screws through the flanges 26 and 28 and into the rib slots 50. No contact of the screws 30 with the interior surface of the tube 24 is necessary and is preferably avoided to eliminate any possibility of deformation of the tube by screw contact, which also allows use of a thin-walled, inexpensive, lightweight tube 24 in comparison with a construction that would be necessary were the screws 30 to be tapped into the tube 24. In this regard, the screws 30 and tube 24 are in non-engaging relation, which results from the combination of sufficient depth of the slots 50 and the aforementioned outwardly converging rib wall configuration.

To provide firm support of the tube 24 on the rib walls 48 without displacement or movement in the assembled condition, the outer surfaces 64 of the rib walls 48 are contoured for substantially flush engagement with the interior surface of the tube 24, and one wall of each rib is formed with a thin sizing ridge 66 along its outer edge. This ridge 66 projects radially sufficiently to assure a snug fit of the tube 24 on the core ribs 46 and can be cut back as required to provide such a snug fit within a reasonable range of tube diameter variances.

To further strengthen the tube 24 without having to increase its thickness and yet allow it to adequately withstand the substantial forces developed in building a package of carpet yarn thereon, the tube may be prestressed in compression by forming it with a free length slightly longer than the length of the core 22,, as illustrated with some exaggeration in FIG. 9. Thus, when the tube 24 is placed on the core 22 and the screws 30 inserted through the flanges 26 and 28 into the rib slots 50 and tightened, the flanges will compress the tube 24 longitudinally until the flanges are in abutment against the core ends, as illustrated in FIG. 4. This compression also firmly seats the ends of the tube 24 against the flanges 26 and 28 and substantially eliminates any yarn catching crevices at the tube and flange junctures. Such crevices can further be avoided by disposing felt rings 68 between the tube 24 and flanges 26 and 28. Alternatively, the flanges could be counterbored for seating of the tube ends therein, which also provides support of the tube against deformation by the yarn forces. This counterboring can be utilized with or without the aforementioned prestressing of the tube 24 and can result in elimination of the reinforcing discs 56 and felt rings 68 with a corresponding material and assembly saving.

With the construction as described, the core 22 is preferably extruded inexpensively from aluminum or plastic so as to be integrally formed as a unitary element, and the tube 24 is inexpensively formed from aluminum, plastic, or paperboard. Other materials could also be used for these parts depending upon the strength requirements for the particular use. In any event, the spider shape of the core 22 and the thin wall capabilities of the tube 24 provide a uniquely lightweight construction that not only facilitates handling but, more importantly, requires less power to rotate the bobbin 20 in a typical winding operation. Furthermore, the simplicity of the parts and the obvious in-line assembly, as illustrated in exploded perspective in FIG. 7, results in significant labor savings in assembly and possible adaptation to automatic assembly operation.

In the embodiment illustrated in FIGS. 4-9, securement of the screws 30 in the rib slots 50 is enhanced by the converging rib walls 48, the'acute angle relation of the rib walls 48 to the interior surface of the tube 24, and the disposition of the reinforcing discs 56. However, depending upon the strength requirements for particular uses, these features need not be used in combination, but could be used separately.

An alternative arrangement for reinforcing the screw securement, is illustrated in the embodiment of FIGS. 10 and 11, wherein a core 70 is shown identical to the core 22 of the embodiment of FIGS. 4-9 except that the rib walls 72 exteriorly extend parallel to the radial center line of the ribs 74, rather than converging as in the preceding embodiment, but the interior of the walls are formed with enlargements 76 adjacent their outer ends to provide a variation to the outwardly converging feature of the embodiment of FIGS. 4-9. Also, this embodiment does not include reinforcing discs, although they could be used if desired for strength requirements. The principal difference between the embodiment of FIGS. 10 and 11 and that of FIGS. 4-9is in the configuration of the interior surface 78 of the exterior cylindrical tube 80. In this embodiment the tube is formed with longitudinally extending inwardly opening grooves 82 formed in its interior surface 78 for seating therein of the outer ends of the rib walls 72. To provide a formation for the grooves, the generally cylindrical interior surface 78 is enlarged inwardly adjacent the grooves to form chordal portions 84 in which the grooves 82 are formed. With this construction, assembly of the tube on the core 70 results in the rib walls 72 extending into the tube grooves 82 so that any tendency of the rib walls 72 to spread due to the force of the screws 86 is prevented, thereby positively securing the screws 86 in the rib walls 70.

A further modification of the securement of screws in the core rib walls is illustrated in FIGS. 12 and 13, wherein a core 90 is shown of a construction similar to that of FIGS. and 11, having striaght rib walls 92 parallel with the radial center lines of the ribs 94 as in the FIG. 10 and 11 embodiment. However, in this embodiment the tube 96 has a cylindrical interior surface without grooves, and securement of screws 98 in the rib slots 100 is reinforced by discs 102 that are not only disposed adjacent the rib walls 92 at the ends of the rib, as in the preceding embodiments, but have flanges 104 extending inwardly along the rib walls 92 adjacent the tube 96 for further strengthening reinforcement of screw securement. In this embodiment, the discs may be formed as metal stamplings with the flanges 104 upset by stamping of a flat sheet. However, the discs 102 may be formed in any desired manner and from any material that provides sufficient reinforcement for the intended purposes.

FIGS. 14-16 illustrate a variation of the embodiments of the present invention which includes a spool assembly 104 provided with end flanges 106 and 108, and an exterior tube 110 corresponding to like elements in the previously described embodiments of the present invention. However, in contrast to such previously described embodiments in which the core of the spool assembly was extruded or otherwise integrally formed as a unitary element, the variation illustrated in FIGS. 14-16 includes an axially extending tubular center portion 112 which is formed as a separate element, and a plurality of longitudinal ribs 114, each of which is likewise formed as a separate element. These separate elements are supported and properly positioned with respect to one another by a pair of identical annular reinforcing members 1 16 mounted, respectively, on each end of the center portion 112. Each reinforcing member 116 includes a plurality of notches 118, corresponding in number to the number of ribs 114, which are designed to receive, at the radially outward portions thereof, the slot-forming walls 120 of the ribs 114 and to receive, at the radially inward portions thereof, the ends of the radially inward portions of the ribs 114. These end portions of the ribs 114 are preferably recessed at 122 to provide tabs 124 that are received by recess 126 in the notches 118. The engagement of the tabs 124 by the recesses 126 prevents any outward movement of the ribs 114 during rotation of the spool assembly 104, and the engagement by the notches 118 of the side wall portions of the ribs 1 14 support the ribs 114 at positions abutting the center portion 112 and projecting radially outward therefrom as best seen in FIG. 15. Also, as in the previously described embodiments, the notches 118 act to prevent spreading of slotforming rib walls 120.

When the attachment recesses 128 are inserted in place as in the previous embodiments, the end flanges 106, 108 act to press the reinforcing members 116 against the ends of the ribs 114 whereby the ribs 114 are properly engaged by the notches 118. However, if desired, the reinforcing members 1 16 may also be held in place by outwardly flaring the ends of the tubular center portion 112 as illustrated by flares 130 in FIG. 14, and the end of the central openings in the reinforcing members 116 may be outwardly flared as at 132 to receive the flared end 130 of center portion 112. Also,

it may be desirable to flare out tabs or portions of the end of center portion 112 rather than the center end, and it may be desirable to only provide flaring at one end of the center portion 112 whereby the reinforcing members 116 and the ribs 114 can be mounted on the center portion 112 at the other, non-flared, end thereof.

It will be apparent that the versatility of the spool assembly 104 will be significantly increased by forming the ribs 114 and center portion 112 as separate elements, yet the structural relationship of these parts is the same as in the previously described embodiments, and the advantages (e.g. strength) obtained therefrom, as previously described, will not be impaired by the added advantage of versatility. Thus, the same ribs 1 14 may be used with larger or smaller center portions and exterior tubes, and the number and form of the ribs used with particular center portions and exterior tubes may be readily increased or decreased to meet varying strength requirements simply by providing a variety of reinforcing members 116 capable of supporting different types of ribs 114. This also importantly allows a variety of spool assemblies to be made from a relatively small inventory as compared with integral core assemblies that require an inventory of each size and shape core and can not have cores and ribs made of different material. Finally, the interchanging of different ribs, center portions and exterior tubes may be accomplished with little or no difficulty because of the fact that these separate elements are not permanently joined to one another and, consequently, they may be selectively disassembled and reassembled.

The aforementioned versatility of the variation of the present invention is demonstrated by FIGS. 14-16, it being noted that the proportionate depth of the slotforming walls of the ribs 114 in FIG. 16 is less than the corresponding proportional depth of the walls 120 in FIGS. 14 and 15, thereby indicating that various ribs 114 can be readily used with the same center portion 112 and exterior tabs 110. Also, it should be noted that the right end of the spool assembly 104 in FIG. 14 has been rotated 45 to illustrate particularly the crosssectional configuration of the reinforcing member 116 between the notches 118 therein.

In any of the foregoing embodiments, the reinforcing discs may be formed of stamped or cast metal or molded plastic or any other suitable construction that provides the necessary reinforcing strength.

Further, the screws in these embodiments may be replaced by other fastening means, such as drive pins seated by a compression fit, which pins may be additionally secured by the use of cement to bond the pins in the core slots.

From the foregoing description of the preferred embodiments, it is apparent that the present invention provides a spool assembly characterized by lightweight, high strength, and inexpensive manufacture, and which provides uniquely strong attachment of the parts in assembled condition.

It is to be understood that various modifications and alterations may be made within the scope of the present invention and that it is not to be limited to the embodiments described and illustrated in detail herein, except as defined in the appended claims.

What is claimed is:

1. A spool assembly comprising a spider-shaped core extending substantially the full length of said spool assembly and having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longitudinal slot defined by a base and a pair of spaced walls extending from said base along the outer edge of said rib, an exterior tube mounted on and structurally supported by said core throughout substantially its full length at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, means fastening said end plates and said core together and being secured substantially fully in said core rib slots, said walls of each rib converging from said base outwardly to at least partially close said slot over said fastening means.

2. A spool assembly according to claim 1 and characterized further in that said outwardly converging rib walls engage said tube at acute angles exteriorly of said slot, so that said tube retains said rib walls against spreading, thereby maintaining said fastening means secured in said core rib slots.

3. A spool assembly according to claim 1 and characterized further in that said fastening means and said tube are in non-engaging relation.

4. A spool assembly according to claim 3 and characterized further in that the free length of said tube is slightly longer than said core, and said fastening means secures said plates against said core, thereby prestressing said tube in compression between said plates.

5. A spool assembly according to claim 1 and characterized further in that said rib walls have outer surfaces thereof contoured for substantially flush engagement with the interior surface of said tube.

6. A spool assembly according to claim 1 and characterized further in that one rib wall of each pair of said rib walls is formed with a thin sizing ridge formed along its outer edge, said ridge projecting sufficiently to provide with the corresponding ridges of the other ribs a relatively snug fit of the tube on the core ribs.

7. A spool assembly according to claim 1 and characterized further in that said core is formed with a cylindrical center bore throughout its length and of uniform diameter for mounting of said spool assembly on spindles of varying lengths.

8. A spool assembly according to claim 1 and characterized further in that said fastening means is a selftapping screw at each core rib end extending through said end plate into said rib slot and tapped into said core rib walls.

9. A spool assembly according to claim 8 and characterized further in that said screw is tapped into said rib at the base of said slot.

10. A spool assembly according to claim 9 and characterized further in that said screw in centrally disposed in said slot with its center spaced from each said rib walls and slot base a distance substantially equivalent to the minor radius of said screw.

11. A spool assembly according to claim 1 and characterized further by an annular reinforcing member at each end of said core and disposed adjacent the rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots.

12. A spool assembly according to claim 1 and characterized further in that said tube has longitudinally extending inwardldy opening grooves formed in its interior surface for seating therein of the outer ends of said rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots.

13. A spool assembly comprising a spider-shaped core having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longtudinal slot defined by spaced walls extending along the outer edge of said rib, an exterior tube mounted on and structurally supported by said core at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, means fastening said end plates and said core together and being secured in said core rib slots, and an annular reinforcing member at each end of said core and disposed adjacent the rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots, said reinforcing members being in the form of flat discs disposed between said core and said end plates and recessed to receive said rib walls for reinforcement thereof.

14. A spool assembly according to claim 13 and characterized further in that the portions of said core ribs between said rib walls and said center portion are recessed longitudinally to receive said discs thereon.

15. A spool assembly according to claim 13 and characterized further in that said discs have flanges extending therefrom along said rib walls inwardly from the ends thereof to strengthen the reinforcement of said rib walls.

16. A spool assembly according to claim 13 and characterized further in that said fastening means and said tube are in non-engaging relation.

17. A spool assembly according to claim 16 and characterized further in that the free length of said tube is slightly longer than said core, and said fastening means secures said plates against said core, thereby prestressing said tube in compression between said plates.

18. A spool assembly according to claim 13 and characterized further in that one rib wall of each rib is formed with a thin sizing ridge formed along its outer edge, said ridge projecting sufficiently to provide with the corresponding ridges of the other ribs a relativeley snug fit of the tube on the core ribs.

19. A spool assembly according to claim 13 and characterized further in that said core is formed with a cylindrical center bore throughout its length and of uniform diameter for mounting of said spool assembly on spindles of varying lengths.

20. A spool assembly according to claim 13 and characterized further in that said fastening means is a selftapping screw at each core rib end extending through said end plate into said rib slot and tapped into said core rib walls.

21. A spool assembly according to claim 13 and characterized further in that said tube has longitudinally extending inwardly opening grooves formed in its interior surface for seating therein of the outer ends of said rib walls to reinforce further said walls against spreading.

22. A spool assembly according to claim 13 and characterized further in that said center portion and said longitudinal ribs of said core are integrally formed as a unitary element.

23. A spool assembly according to claim 13 and characterized further in that said center portion and each of said longitudinal ribs of said core are formed as separate elements.

24. A spool assembly comprising a spider-shaped core having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longitudinal slot defined by spaced walls extending along the outer edge of said rib, an exterior tube mounted on and structurally supported by said core at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, means fastening said end plates and said core together and being secured in said core rib slots, and an annular reinforcing member at each end of said core and disposed adjacent the rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots, said center portion and each of said longitudinal ribs of said core being formed as separate elements, and said annular reinforcing members being mounted about said center core portion and engaging each of said longitudinal ribs endwise to support said longitudinal ribs at a position abutting said center core portion and projecting radially outward therefrom.

25. A spool assembly according to claim 24 and characterized further in that said annular reinforcing members are formed with a plurality of notches arranged to receive the endwise portions of said longitudinal ribs, said notches engaging the outer surfaces of said rib walls to reinforce said walls against spreading.

26. A spool assembly according to claim 24 and characterized further in that said annular reinforcing members are mounted, respectively, at each end of said center portion, and in that at least one end portion of said center portion is flared outwardly to engage an end face of the annular reinforcing member mounted thereat and thereby to retain said annular reinforcing member in engagement with said ribs.

27. A spool assembly comprising a spider-shaped core having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longitudinal slot defined by spaced walls extending along the outer edge of said rib, and exterior tube mounted on and structurally supported by said core at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, and means fastening said end plates and said core together and being secured in said core rib slots, said tube having longitudinally extending inwardly opening grooves formed in its interior surface for seating therein of the outer ends of said rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots.

28. A spool assembly according to claim 27 and characterized further in that said tube is enlarged inwardly adjacent said grooves to provide a formation for said grooves.

29. A spool assembly according to claim 27 and characterized further in that the interior surface of said tube is generally cylindrical with chordal portions in which said grooves are formed.

30. A spool assembly according to claim 27 and characterized further in that said fastening means and said tube are in non-engaging relation.

31. A spool assembly according to claim 30 and characterized further in that the free length of said tube is slightly longer than said core, and said fastening means secures said plates against said core, thereby prestressing said tube in compression between said plates.

32. A spool assembly according to claim 27 and characterized further in that one rib wall of each rib is formed with a thin sizing ridge formed along its outer edge, said ridge projecting sufiiciently to provide with the corresponding ridges of the other ribs a relatively snug fit of the tube on the core ribs.

33. A spool assembly according to claim 27 and characterized further in that said core is formed with a cylindrical center bore throughout its length and of uniform diameter for mounting of said spool assembly on spindles of varying lengths.

34. A spool assembly according to claim 27 and characterized further in that said fastening means is a selftapping screw at each core rib and extending through said end plate into said rib slot and tapped into said core rib walls.

g;;g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,881,668 Dated May 6, 1975 Inventor) George A. Poteat It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Abstract page, line 21, after sizing" insert ridge Column2, line 46, after "the" delete "ribs" and insert therefor rib Column 7, line 6, delete "striaght" and insert therefor straight Column 7, line 17, delete "stamplings" and insert therefor stampings Column 9 line 66 delete "inwardldy" and insert therefor inwardly Column 10,

line 7, delete "longtudinal" and insert therefor longitudinal Column 10, line 43, delete "relativeley" and insert therefor relatively Figures 3, 4 and 6, should appear as shown on the attached sheets.

Signed and Sealed thls twenty-third Day Of September 1975 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN :NH I IK U /7 W ('mnmixsium'r uj'lalcnts um! TIdt/LHltlfkfi UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,881,668 Dated May 6, 1975 lnventofls) Georfe A. Poteat P 2 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Signed and Scaled this twenty-third D 3y Ofv September 1975 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN .-Itrcsling ()j'j'iver ('nmmiSsinncr nj'lurenls and Trademarks FORM PO-HJSO (IO-69) USCOMMDC 60376-p69 U 5 COVIRNMENY PRINTING FIFFICE 86Q q'7o UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. Dated George A. Poteat Page 3 Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Fig 4 30 x E Q E 24 L 4 5 5 20 l 4 I 4a 46 z\ 22 a k w 44 s 30 Signed and Sealed this twenty-third Day of Septemberl975 [SEAL] FOR Arrest:

RUTH C. MASON C. MARSHALL DANN :IIHSII'HX ff M ('umnuIx'xium'r uj'lare'nrs and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, D d May 6,

lnventofls) George A. Poteat M Page 4 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Signed and Sealed this twenty-third D3) Of September 1975 [SEAL] Arrest:

RUTH C. MASON C MARSHALL DANN Arresting Officer ('ummixsimu'r uj' Iulvnrs and Trademarks F ORM PO- 05O (NJ-G9) USCOMM-DC 603764 69 U 5 GfiVEF-JNMENY PRINTING OFFICE 5g 930 

1. A spool assembly comprising a spider-shaped core extending substantially the full length of said spool assembly and having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longitudinal slot defined by a base and a pair of spaced walls extending from said base along the outer edge of said rib, an exterior tube mounted on and structurally supported by said core throughout substantially its full length at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, means fastening said end plates and said core together and being secured substantially fully in said core rib slots, said walls of each rib converging from said base outwardly to at least partially close said slot over said fastening means.
 2. A spool assembly according to claim 1 and characterized further in that said outwardly converging rib walls engage said tube at acute angles exteriorly of said slot, so that said tube retains said rib walls against spreading, thereby maintaining said fastening means secured in said core rib slots.
 3. A spool assembly according to claim 1 and characterized further in that said fastening means and said tube are in non-engaging relation.
 4. A spool assembly according to claim 3 and characterized further in that the free length of said tube is slightly longer than said core, and said fastening means secures said plates against said core, thereby prestressing said tube in compression between said plates.
 5. A spool assembly according to claim 1 and characterized further in that said rib walls have outer surfaces thereof contoured for substantially flush engagement with the interior surface of said tube.
 6. A spool assembly according to claim 1 and characterized further in that one rib wall of each pair of said rib walls is formed with a thin sizing ridge formed along its outer edge, said ridge projecting sufficiently to provide with the corresponding ridges of the other ribs a relatively snug fit of the tube on the core ribs.
 7. A spool assembly according to claim 1 and characterized further in that said core is formed with a cylindrical center bore throughout its length and of uniForm diameter for mounting of said spool assembly on spindles of varying lengths.
 8. A spool assembly according to claim 1 and characterized further in that said fastening means is a self-tapping screw at each core rib end extending through said end plate into said rib slot and tapped into said core rib walls.
 9. A spool assembly according to claim 8 and characterized further in that said screw is tapped into said rib at the base of said slot.
 10. A spool assembly according to claim 9 and characterized further in that said screw in centrally disposed in said slot with its center spaced from each said rib walls and slot base a distance substantially equivalent to the minor radius of said screw.
 11. A spool assembly according to claim 1 and characterized further by an annular reinforcing member at each end of said core and disposed adjacent the rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots.
 12. A spool assembly according to claim 1 and characterized further in that said tube has longitudinally extending inwardldy opening grooves formed in its interior surface for seating therein of the outer ends of said rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots.
 13. A spool assembly comprising a spider-shaped core having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longtudinal slot defined by spaced walls extending along the outer edge of said rib, an exterior tube mounted on and structurally supported by said core at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, means fastening said end plates and said core together and being secured in said core rib slots, and an annular reinforcing member at each end of said core and disposed adjacent the rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots, said reinforcing members being in the form of flat discs disposed between said core and said end plates and recessed to receive said rib walls for reinforcement thereof.
 14. A spool assembly according to claim 13 and characterized further in that the portions of said core ribs between said rib walls and said center portion are recessed longitudinally to receive said discs thereon.
 15. A spool assembly according to claim 13 and characterized further in that said discs have flanges extending therefrom along said rib walls inwardly from the ends thereof to strengthen the reinforcement of said rib walls.
 16. A spool assembly according to claim 13 and characterized further in that said fastening means and said tube are in non-engaging relation.
 17. A spool assembly according to claim 16 and characterized further in that the free length of said tube is slightly longer than said core, and said fastening means secures said plates against said core, thereby prestressing said tube in compression between said plates.
 18. A spool assembly according to claim 13 and characterized further in that one rib wall of each rib is formed with a thin sizing ridge formed along its outer edge, said ridge projecting sufficiently to provide with the corresponding ridges of the other ribs a relativeley snug fit of the tube on the core ribs.
 19. A spool assembly according to claim 13 and characterized further in that said core is formed with a cylindrical center bore throughout its length and of uniform diameter for mounting of said spool assembly on spindles of varying lengths.
 20. A spool assembly according to claim 13 and characterized further in that said fastening means is a self-tapping screw at each core rib end extending through said end plate into said rib slot and tapped into said core rib walls.
 21. A spool assembly according to claim 13 and chaRacterized further in that said tube has longitudinally extending inwardly opening grooves formed in its interior surface for seating therein of the outer ends of said rib walls to reinforce further said walls against spreading.
 22. A spool assembly according to claim 13 and characterized further in that said center portion and said longitudinal ribs of said core are integrally formed as a unitary element.
 23. A spool assembly according to claim 13 and characterized further in that said center portion and each of said longitudinal ribs of said core are formed as separate elements.
 24. A spool assembly comprising a spider-shaped core having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longitudinal slot defined by spaced walls extending along the outer edge of said rib, an exterior tube mounted on and structurally supported by said core at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, means fastening said end plates and said core together and being secured in said core rib slots, and an annular reinforcing member at each end of said core and disposed adjacent the rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots, said center portion and each of said longitudinal ribs of said core being formed as separate elements, and said annular reinforcing members being mounted about said center core portion and engaging each of said longitudinal ribs endwise to support said longitudinal ribs at a position abutting said center core portion and projecting radially outward therefrom.
 25. A spool assembly according to claim 24 and characterized further in that said annular reinforcing members are formed with a plurality of notches arranged to receive the endwise portions of said longitudinal ribs, said notches engaging the outer surfaces of said rib walls to reinforce said walls against spreading.
 26. A spool assembly according to claim 24 and characterized further in that said annular reinforcing members are mounted, respectively, at each end of said center portion, and in that at least one end portion of said center portion is flared outwardly to engage an end face of the annular reinforcing member mounted thereat and thereby to retain said annular reinforcing member in engagement with said ribs.
 27. A spool assembly comprising a spider-shaped core having an axially extending center portion and a plurality of longitudinal ribs projecting radially outward from said center portion, each said rib having an outwardly opening longitudinal slot defined by spaced walls extending along the outer edge of said rib, and exterior tube mounted on and structurally supported by said core at the outer edges of said walls, end plates at each end of said core extending radially outward to said tube for retention of said tube on said core between said plates, and means fastening said end plates and said core together and being secured in said core rib slots, said tube having longitudinally extending inwardly opening grooves formed in its interior surface for seating therein of the outer ends of said rib walls to reinforce said rib walls against spreading and thereby retain said fastening means in said slots.
 28. A spool assembly according to claim 27 and characterized further in that said tube is enlarged inwardly adjacent said grooves to provide a formation for said grooves.
 29. A spool assembly according to claim 27 and characterized further in that the interior surface of said tube is generally cylindrical with chordal portions in which said grooves are formed.
 30. A spool assembly according to claim 27 and characterized further in that said fastening means and said tube are in non-engaging relation.
 31. A spool assembly according to claim 30 and characterized further in that tHe free length of said tube is slightly longer than said core, and said fastening means secures said plates against said core, thereby prestressing said tube in compression between said plates.
 32. A spool assembly according to claim 27 and characterized further in that one rib wall of each rib is formed with a thin sizing ridge formed along its outer edge, said ridge projecting sufficiently to provide with the corresponding ridges of the other ribs a relatively snug fit of the tube on the core ribs.
 33. A spool assembly according to claim 27 and characterized further in that said core is formed with a cylindrical center bore throughout its length and of uniform diameter for mounting of said spool assembly on spindles of varying lengths.
 34. A spool assembly according to claim 27 and characterized further in that said fastening means is a self-tapping screw at each core rib and extending through said end plate into said rib slot and tapped into said core rib walls. 